A bearing to be used at, for example, a joint section of an arm of construction machinery is required to have excellent wear resistance because remarkably large surface pressure is applied to a bearing surface of the bearing. As the bearing of this type, for example, there are known a bearing obtained by cutting casting alloy and a bearing obtained by embedding particles of graphite in a sliding surface in a spotted manner. However, both of the bearings have a problem of high production cost. Accordingly, instead of those bearings, a sintered bearing made of sintered metal excellent in moldability is used. For example, Patent Literature 1 discloses, as a bearing for construction machinery, a sintered bearing that is made of sintered metal obtained by dispersing copper in iron-carbon-based alloy containing martensitic structure.